Stool quality and stool frequency are generally determined by five factors: food ingredient digestibility, fiber level, health status, activity level, and water intake. When these factors are balanced, stools are generally formed, firm, dark, and exhibit a relatively reduced odor. Stools exhibiting these properties are considered to be good quality stools. If the factors are not balanced, stools are generally soft, loose, watery, light-colored, and exhibit a relatively increased odor. Stools exhibiting these properties, particularly loose, watery stools, are considered to be poor quality stools.
Poor stool quality and irregular stool frequency can be caused by various factors, e.g., abnormal intestinal motility, increases in intestinal permeability, the presence of nonabsorbable osmotically active substances in the intestine, or agents that cause diarrhea. Similarly, some animal foods, particularly those known in the art as chunk and gravy animal foods, can cause poor stool quality. Often, an animal consuming such foods has a fecal discharge that is irregular and undesirable. Such discharge is generally characterized by frequent loose, watery stools. In some instances, the discharge may be classified as diarrhea.
Accordingly, new methods and compositions are required which can affect stool quality of an animal. U.S. patent application Ser. No. 11/566,512 (the '512 application) filed Dec. 4, 2006 (the contents of which are herein incorporated by reference) discloses adjusting the balance of metabolizable cations to metabolizable anions consumed by the animal to affect stool quality. It has generally been found that increasing the balance of metabolizable cations to metabolizable anions will result in firmer stool quality and reduced stool output. Conversely, decreasing the balance of metabolizable cations to metabolizable anions will result in looser stool and increased stool output.
While the '512 application describes methods for altering stool quality and/or frequency for adult dogs, the dietary requirements of adult dogs and puppies are quite different. For example, puppies generally experience rapid growth and development; thus they generally require significantly more nutrition than adult dogs and of a different nutritional composition. For example, puppies require higher calcium levels due to their rapid bone growth. Similarly, the stool of adult dogs and puppies are typically of different quality and it is known that a dog produces substantially firmer stool than a puppy, partly in response to their different diets and nutritional requirements. Thus, the cation and anion balance disclosed in the prior art, while suitable for adult dogs, may be unsuitable for improving the stool quality of a puppy. The inventors of the present invention have discovered that the stool quality of a puppy may be improved by modifying the dietary cation and anion balance of a food composition consumed by the animal such that the dietary cation and anion balance is from about 50 to about 300 mEq.